package edu.idei.lor;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.index.IndexWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Date;

/** Index all text files under a directory. */
public class IndexFiles {

	private IndexFiles() {
	}
	static final File INDEX_DIR = new File("index");

	public static void main(String[] args) {
		String usage = "java org.apache.lucene.demo.IndexFiles <root_directory>";
		if (args.length == 0) {
			System.err.println("Usage: " + usage);
			System.exit(1);
		}

		if (INDEX_DIR.exists()) {
			System.out.println("Cannot save index to '" + INDEX_DIR + "' directory, please delete it first");
			System.exit(1);
		}

		final File docDir = new File(args[0]);
		if (!docDir.exists() || !docDir.canRead()) {
			System.out.println("Document directory '" + docDir.getAbsolutePath() + "' does not exist or is not readable, please check the path");
			System.exit(1);
		}

		Date start = new Date();
		try {
			IndexWriter writer = new IndexWriter(INDEX_DIR, 
					new StandardAnalyzer(), true);
			System.out.println("Indexing to directory '" + INDEX_DIR + "'...");
			indexDocs(writer, docDir);
			System.out.println("Optimizing...");
			writer.optimize();
			writer.close();

			Date end = new Date();
			System.out.println(end.getTime() - start.getTime() + " total milliseconds");

		} catch (IOException e) {
			System.out.println(" caught a " + e.getClass() +
					"\n with message: " + e.getMessage());
		}
	}

	static void indexDocs(IndexWriter writer, File file) throws IOException {
		// do not try to index files that cannot be read
		if (file.canRead()) {
			if (file.isDirectory()) {
				String[] files = file.list();
				// an IO error could occur
				if (files != null) {
					for (int i = 0; i < files.length; i++) {
						indexDocs(writer, new File(file, files[i]));
					}
				}
			} else {
				System.out.println("adding " + file);
				try {
					writer.addDocument(FileDocument.Document(file));
				} // at least on windows, some temporary files raise this exception with an "access denied" message
				// checking if the file can be read doesn't help
				catch (FileNotFoundException fnfe) {
				}
			}
		}
	}
}
